The present invention relates to a defect inspecting apparatus for measuring electric characteristics of an electronic element such as a semiconductor chip by use of a fine probe, and in particular, to a defect inspecting apparatus using particularly a charged-particle beam unit for measuring electric characteristics of an electronic element by bringing the probe into direct contact with the electronic element.
To inspect electric defects of a complicated electronic circuit formed on a semiconductor chip, there have been used defect inspecting apparatuses such as an Electron Beam (EB) tester and a prober unit. The EB tester inspects an electrically defective point of a Large-Scale Integrated (LSI) circuit as below. When the tester emits an electron beam onto a measuring point, secondary electrons are emitted from the measuring point. The amount of such emitted secondary electrons varies depending on a voltage value at the point to thereby detect an electrically defective point of the LSI circuit. In the prober unit, a plurality of probe needles disposed according to positions of characteristic measuring pads of an LSI circuit or mechanical probes are brought into contact with the measuring pads and/or plugs to measure electric characteristics of the LSI circuit. When such EB tester or prober unit is employed for the defect inspection, an operator or a user of the apparatus confirms a contact position of each probe through a manual operation while viewing an image of wiring produced by an optical microscope or a Scanning Electron Microscopy (SEM) image generated by a Scanning Electron Microscope (SEM).
Since the circuit pattern formed on a semiconductor element such as an LSI device has been complicated these days, it becomes difficult to quickly move a probe to an optimal position. To overcome the difficulty, there exists a technique called Computer Aided Design (CAD) navigation to reduce the period of time required for moving the probing. That is, in the inspection of a semiconductor device, a wiring layout of the device is displayed in association with an actual image at desired positions on the device, the image being viewed by the operator for the inspection.
To observe the SEM image, a scanning electronic microscope is employed to scan a sample using a primary electron beam to produce a scanned image of a fine pattern sample of a semiconductor. Such apparatus to observe a fine pattern sample includes an image shift function to correctly move an emission area of the primary electron beam or an observing field thereof to an observing point on the sample by use of a deflector including electrically two stages. The deflector electrically deflects the primary electron beam in a range from several micrometers (μm) to about ten μm.
JP-A-2000-147070 describes a probing device including a display section to display a probe information screen indicating information to make a probe achieve a desired operation. The probing device also includes a function to display a sample and the probe in the probe information screen of the display section, to present on the display section a probe operation screen area to move the probe thereto, and to move the probe by a probe controller in response to an operation signal of the probe operation screen area. The probing device further includes a function in which when the operator respectively designates a current position of a tip end of the probe displayed in the probe information screen and a moving target position of the tip end in the probe information screen, the device calculates a moving length or distance from the current position to the target position and makes the probe controller according to the moving distance to move the probe to the target position. The probing device also includes a function to select one of plural probes.
JP-A-9-326425 describes a defect inspecting apparatus including a vacuum chamber, a probing needle and a probing needle moving mechanism to move the probing needle which are disposed in the vacuum chamber, a sample stand to mount a sample thereon, a charged particle source, an emitting unit to emit a charged-particle beam from the charged particle source, a detector to detect charged particles from the sample, a unit to apply a voltage between the probing needle and the sample and/or between the probing needles, and a unit to measure electric characteristics of the sample.
JP-A-2002-523784 describes a probe station to deliver an electric test signal to an integrated circuit as an object to be inspected.